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Biomedical subjects

E Cofrancesco

Publications and source records attributed to E Cofrancesco.

54 records · Page 3Linked to original sources
PubMed1981

GAGs-potentiated inhibition of thrombin, factor Xa and plasmin in plasma and in a purified system containing antithrombin III - correlation with total charge density.

The ability of heparin and related glycosaminoglycans (GAGs) to accelerate the inhibition of thrombin, factor Xa and plasmin in plasma and in a purified system containing antithrombin III (At III) was studied using chromogenic peptide substrate assays. There was good correlation between the charge density of the mucopolysaccharides and the activities investigated. While the difference between potentiation of the antithrombin activity by GAGs in plasma and in the purified system was slight, the inhibition of factor Xa in plasma was more pronounced than in the presence of purified At III, indicating the mechanisms for GAGs-potentiated inhibition of thrombin and factor Xa are not identical. For the antiplasmin activity, there was a good correlation between the chemical structure and biological activity only in the pure system, confirming that the antithrombin-GAG complex plays a very limited role in the inactivation of plasmin in plasma.

Antithrombins↗
PubMed1981

Daunorubicin and platelet function.

The influence of Daunorubicin on some platelet functions in vitro was investigated, using different concentrations of the drug (0.01-0.02-0.04 microgram/ml). Daunorubicin was shown to inhibit Collagen and Thrombin induced platelet aggregation and the intensity of inhibition on both drug concentration and the time of preincubation. Daunorubicin was also shown to inhibit the release reaction, the platelet prostaglandin pathway and the availability platelet factor 3; the drug at concentrations for clinical use does not damage the platelet membrane, as is the case with the freezing and thawing test, in platelet uptake of 14C-serotonin and as confirmed by the electron microscope. When very high doses (0.16 mg) of Daunorubicin are used, lysis of the platelets can be observed and this is confirmed under the electron microscope by the presence of empty platelets with fractures at the level of the cytoplasmid membrane. Finally, Daunorubicin causes irreversible inhibition of reptilase clot-retraction, even if this is less severe than with Vincristine. Working with gel-filtered platelets, it would appear that the inhibition exercised by the drug on platelet reactions is not caused through modifications in Ca++ metabolism. The authors suggest that Daunorubicin, at the dosages used clinically, induces in vitro thrombocytopathy without damaging the cellular membrane as confirmed by the electron microscope. This impairment of platelet functions could play a part in hemorrhagic diathesis observed during Daunorubicin therapy.

Blood Platelets↗
PubMed1975

Human platelet aggregation by mixed cryoglobulins.

Glomerulonephritis in idiopatic mixed cryoglobulinemia represents perhaps a glomerular damage by immune complexes. In this study, a sigmoidal-like curve was obtained after addition of 13 different mixed cryoglobulins to both autologous and isologous platelet-rich plasma, tested in platelet aggregometer. The lag phase of the curve corresponds to platelet phagocytosis of cryoglobulin-binding ferritin, as shown in electron microscopy and the optical density decrease phase corresponds to the aggregation of platelets that shows the same ultrastructural characteristics of ADP-induced platelet aggregation. This platelet aggregation is inhibited by different drugs. Intraglomerular platelet aggregation by cryoglobulins might play a key role in determining the glomerular damage in cryoglobulinemia by the release of nucleotides and vasoactive amines.

Blood Platelets↗
PubMed1975

Anti-heparin activity of a macroglobulin from a patient with breast adenocarcinoma.

We describe a case of IgM paraproteinemia, whose macroblogulin reacted anomalously with heparin. Anti-heparin activity of the paraprotein was suggested by insensibility of the patient's plasma to heparin in heparin-thrombin clotting time. Moreover, the presence of heparin in the medium markedly reduced the inhibitory effect of the paraprotein on platelet aggregation by ADP.

Adenocarcinoma↗
PubMedDate not supplied

A turbidimetric assay method for studying antibody-induced lysis of hapten-coated erythrocytes.

A method is described, based on the application of trubidimetry for study of antibody-mediated complement-dependent lysis of hapten-coated erythrocytes. The procedure is simple, reliable and sensitive. Time-rate studies over the entire range of interaction between the reactants are possible, with a minimal consumption of materials and time. The method also gives the possibility of adding substances to the reaction mixture, even at high concentrations, without introducing errors by multiple handling and washing.

Animals↗
PubMedDate not supplied

Treatment of chronic disseminated Geotrichum capitatum infection with high cumulative dose of colloidal amphotericin B and itraconazole in a leukaemia patient.

A case of disseminated granulomatous Geotrichum capitatum infection is reported. A young patient with blastic crisis of chronic myelogenous leukaemia developed septicaemia caused by G. capitatum in the post-chemotherapy aplastic phase. Subsequently, disseminated infection of the liver, spleen, pancreas and kidneys was observed. Treatment with high cumulative doses of a lipid formulation of amphotericin B (Amphocil, 20.2 g in 11 weeks) and maintenance with itraconazole resolved clinical manifestations of G. capitatum granulomatous disseminated disease and controlled reactivation of the infection during the two subsequent courses of cytotoxic chemotherapy.

Adolescent↗
PubMedDate not supplied

Efficacy of liposomal amphotericin B (AmBisome) in the eradication of Fusarium infection in a leukaemic patient.

We recently succeeded in eradicating a Fusarium infection by treatment with liposomal amphotericin B (L-AmB). The patient, a 22-year-old man with acute lymphoblastic leukaemia (ALL), developed fever and diffuse cutaneous maculopapular necrotising nodules during post-chemotherapy neutropenia. Fusarium verticilloides was isolated from the skin, and hyphae were observed on direct microscopy. Despite increased WBC and amphotericin B (AmB) treatment (0.7 mg/kg/day for 11 days), he remained febrile and a chest X-ray revealed pulmonary lesions. Fusarium infection was confirmed by bronchial aspirate. AmB was increased to 1 mg/kg/day, and continued for 16 days (total dose 1630 mg). A slight improvement was observed at tomography, but nephrotoxicity developed. Treatment was changed to L-AmB (3 mg/kg/day). The patient received this drug for 20 days (total dose of 3850 mg) with complete regression of the pulmonary lesions. No adverse event occurred, and nephrotoxicity resolved. The patient was discharged from hospital cured of the Fusarium infection and in clinical and haematological remission. No relapse of fusariosis occurred, despite additional courses of intensive chemotherapy. Ambisome could represent an important advance in antifungal treatment since it allows aggressive treatment and eradication of mycoses refractory to conventional therapy while avoiding renal toxicity.

Adult↗
PubMedDate not supplied

Ciprofloxacin for infection prophylaxis in granulocytopenic patients with acute leukemia.

Forty consecutive neutropenic patients with acute leukemia receiving oral ciprofloxacin (500 mg twice daily) and ketoconazole (200 mg daily) for selective intestinal decontamination were compared retrospectively with 33 comparable patients treated with polymyxin E (1,500,000 U x 3/day) and nystatin (1,000,000 U x 3/day). The incidence of febrile episodes was slightly lower in ciprofloxacin treated patients (87.5% vs 100%). No gram-negative sepsis was observed in this group compared with seven cases in patients receiving polymyxin E (p less than 0.01). Furthermore, eight patients in ciprofloxacin group (20%) had gram-positive sepsis, compared with five (15.5%) in the polymyxin E group. The incidence of documented fungal infections was similar in the two groups. Ciprofloxacin appears to be an effective agent for the prevention of gram-negative infections in granulocytopenic patients with acute leukemia, but may contribute to a shift in the type of infections in these patients towards those caused by gram-positive microorganisms, intrinsically fairly sensitive or with acquired drug resistance.

Agranulocytosis↗
PubMedDate not supplied

[rt-PA in extracardiac thromboembolic vascular occlusions].

Recombinant tissue plasminogen activator (rt-PA) is a thrombolytic agent characterized by elevated but not absolute fibrin specificity. However, its therapeutic dose is high and associated with a variable degree of systemic activation of the fibrinolytic system. Thrombolytic drugs are widely used in acute myocardial infarction and have now begun to be considered for deep vein thrombosis (DVT), pulmonary embolism (PE), and peripheral artery thrombosis (PAT) as well. Although anticoagulant therapy is effective in reducing the immediate complications of venous thromboembolism, thrombolytic therapy has various advantages over anticoagulant therapy, including lysis of thrombi with recanalization of venous circulation, reduction of venous valve damage and prevention of post-phlebitic syndrome. The different dosage regimens of rt-PA recently evaluated (0.71 to 1.76 mg/kg/24 h for 2-4 days) in DVT have caused consistent thrombolysis but also excessive bleeding. The optimal therapeutic range for rt-PA in DVT remains to be determined. Thrombolytic therapy is superior to heparin treatment only in hemodynamically compromised patients with massive PE. The minor systemic fibrinolytic effect and the faster action on thrombi of rt-PA compared with the first generation thrombolytic agents, streptokinase (SK) and urokinase (UK), are very interesting and explain the positive results recently obtained in PE with this drug (50 mg over 2 h, followed, if necessary, by 40-50 mg over 4-5 h) by Goldhaber and Verstraete.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗